The present invention relates to ostomy appliances and in particular to the portion of the ostomy appliance used to attach the appliance to the body of the user.
A person who has lost the normal function of his bowel or bladder due to birth defect, injury or disease, or other disorder, often undergoes the surgery known as an "ostomy." In this type of surgery, the surgeon opens a hole in the abdominal wall of the patient, and pulls a section of the bladder conduit or bowel to the skin surface where it is attached. In the case of a bowel attachment the surgery is termed an ileostomy when the small intestine is involved and a colostomy when the large intestine is involved, and in the case of a bladder the surgery is called a urostomy.
The hole in the skin and attached end of the bladder conduit or intestine is termed the "stoma," and the surrounding skin area is termed the "peristomal area." The ostomy is sometimes a temporary procedure, with resumption of more normal bowel or bladder function several months later and closure of the stoma, but in many cases the ostomy is permanent. The stoma provides an open conduit through which a constant or intermittent efflux of waste material occurs, fecal material in the cases of ileostomy and colostomy and urine in the case of a urostomy. The waste material is collected in a bag-like ostomy appliance which is worn by the user and replaced by the user as required every few days.
At the present time, the attachment of the ostomy appliance to the user typically requires a variety of separate materials. A skin barrier is used, typically a disk or rectangular pad made of either karaya gum or Stoma-Leasine, both of which are gum-like substances and relatively inflexible. The user must cut a hole in this skin barrier to match his particular stoma, the stomas of different patients varying in size and shape. This step is quite difficult because of the thickness and stiffness of the skin barrier, particularly for elderly patients who are the most common subject of ostomy surgery.
After cutting an opening in the skin barrier to the appropriate size and shape the following steps are typical to install the appliance. The user sprays the peristomal area with a medicated skin barrier spray, typically out of an aerosol spray can. The user then coats the skin barrier with karaya glue, out of a tube, and glues that plate to the peristomal skin. The user then cuts a hole in the ostomy appliance to closely match the hole in the skin barrier. The appliance has an adhesive portion either on the surface of the bag or an attached flap. The adhesive has a protective cover sheet which the user peels off to expose the adhesive layer which is pressed firmly against the skin barrier. The bag may then be covered with a cloth cover to reduce skin irritation where it rests against the abdomen or thigh and may be fastened with a belt to help keep it from pulling off. In some instances the adhesive portion of the appliance is mounted directly on the skin without an intervening skin barrier.
The above process must be repeated every two or three days on average because current appliances typically come loose, develop leaks or cause skin irritation, all of which require attention and a fresh appliance. Performing the entire operation, and in particular performing it effectively so that the skin barrier and/or the adhesive portion of the appliance fits closely to the stoma, is very difficult; sometimes as many as three appliances must be mounted in one day before a good seal is obtained. Moreover, the user must carry an assemblage of supplies, including spare appliances, skin barriers, aerosol sprays, tubes of glue, containers of glue remover, bag covers, etc., wherever he goes to be prepared to recover from a leak or detachment of the appliance.
Not only is the procedure described above difficult and inconvenient, but it is far less effective than desired. Waste material is extremely irritating to the skin if allowed to contact the skin for significant periods of time. Unfortunately, the relatively thick skin barriers now in use provide a space where the waste material can pool. The materials used in the skin barrier melt when exposed to waste material, thus allowing the waste materials to work their way between the skin barrier and the skin. This exposes the delicate peristomal skin to the waste materials which burn and cause the skin to disintegrate. Also, the seal between the skin barrier and the skin can be broken which allows the appliance to leak, or even fall off, resulting in acute embarrassment to the user. Indeed, the fear of such an accident coupled with the difficulty of carrying the implements for changing the appliance and actually making the change away from home often causes ostomy patients to act as housebound invalids, when in fact they should be able to lead almost normal, active lives.
The systems used to attach the current appliances to the body do not work well for a number of reasons. Already mentioned is the fact that the skin barriers are often made of materials which soften and dissolve or "melt," in contact with aqueous material, thus allowing fluids to work their way between the skin barrier and the skin and thereby loosen the adhesion and furthering the melting area until finally the seal is completely breached causing leakage and/or detachment of the appliance.
Another problem with the attachment of the current appliances is that the skin barriers are relatively inflexible and non-stretchy. Furthermore, the plastic sheeting material of which the appliances are made, including the adhesive area are not very stretchy, being typically made of relatively thick material such as vinyl or polyethylene, or fibrous, nonwoven fabric.
Inflexibility of the surface that is bonded to the skin contributes to leakage and detachment because as the skin bends and bulges in response to the wearer's body movements, the relatively stiff attachment surface resists such bending and tends not to follow such bending closely. Therefore, under such bending movements a force is set up between the skin and the skin barrier which tends to peel the flexible and bending skin away from the relatively inflexible attachment surface.
Also, inflexibility of the material that is adhered to the skin prevents it from being molded closely to the contour of the skin immediately adjacent to the stoma. This is particularly a problem for recessed stomas where the space between the skin and the skin barrier must be filled with karaya paste or rubber gaskets, etc. This becomes a make-shift rig at best.
Furthermore, body movements tend to stretch and contract the skin laterally (along its surface). If the skin is attached to a surface which is non-stretchy, relative to the skin, then the stretching and contracting skin will set up shear forces at the surface of adhesion between the skin and the appliance, and those shear forces will tend to break the adhesive bond.
The inability of the surfaces of adhesion of the existing attachment systems to follow and conform closely to the skin in flexure and in lateral stretching and contracting promotes the breaking of the bond; and once the bond is broken the skin and the adhesive surfaces tend not to readhere easily, and furthermore they can easily become wet with fluids from within the appliance and/or from perspiration from the skin directly, and such wetness can totally prevent readhesion. Thus as the body and skin stretch and move and gradually pull loose from the appliance the unbonded domain remains unbonded and gradually extends until finally leakage or detachment results.